Biology subjects

Nazar, F. N.

Publications and source records attributed to Nazar, F. N..

3 recordsLinked to original sources

bioRxiv2025

Integrated environmental drivers and evolutionary history reveal conserved patterns of avian exposure to West Nile and Saint Louis encephalitis viruses

The increasing threat of emerging vector-borne diseases, affecting both humans and wildlife, necessitates a nuanced understanding of the complex interactions among vectors, hosts, and pathogens. Focusing on West Nile Virus (WNV) and Saint Louis encephalitis Virus (SLEV) activity in avian communities of central and northern Argentina, this study delves into the intricate dynamics of exposure risk employing phylogenetic mixed models. Contrary to expectations, ecological traits displayed negligible influence on exposure risk. Instead, temperature seasonality and altitude, emerged as crucial predictors. The phylogenetic signal indicated a conserved susceptibility along the avian evolutionary tree, with Furnariidae, Turdidae and Columbidae families exhibiting higher exposure risk. These findings challenge prevailing notions about the dominant role of ecological traits in mosquito-borne pathogens. The study underscores the need for a holistic understanding, emphasizing the intricate interplay of environmental, phylogenetic, and ecological elements in shaping avian exposure to WNV and SLEV, offering vital insights for future research and public health strategies.

ecology↗

bioRxiv2024

Chronic Stress effects on Immune-Neuroendocrine matrix in Coturnix coturnix, analyses from an ontogenetic perspective

Immune-neuroendocrine characteristics can be used to classify individuals according to their physiological profiles or phenotypes (INPs). In avian models such as quail and domestic chickens, three subgroups based on INPs have been defined: Lewis-like (pro-inflammatory polarization), Fischer-like (anti-inflammatory polarization), and an intermediate INP. This study investigates the stability and alterations of INPs throughout ontogeny, from juvenile to adult stages in four time-points including an exposure to unpredictable and diverse chronic stress (CS) during early adulthood. We measured corticosterone levels, pro-(IFN-{gamma} and IL-1{beta}) and anti-inflammatory (IL-13, IL-4) cytokines, phytohemagglutinin (PHA-P) lymphoproliferative response, anti-sheep red blood cells antibody (Ab SRBC) response, and leukocyte distribution frequency. Cluster analyses were conducted to classify bird based on their similarities across all analyzed variables, to thereby establish their INP at each time point. The extreme Lewis- or Fischer-like profiles were less represented in juvenile and pre-stress adult birds showing a higher proportion of individuals with an intermediate profile. Following CS exposure, the prevalence of Lewis-like and Fischer-like profiles increased. This shift persisted 10 weeks later as birds matured to an advanced egg-laying stage, with females predominantly exhibiting the Fischer-like INP, and males the Lewis-like INP. The observed shift in INP distribution following CS towards more polarized Lewis- and Fisher-like profiles implies a more even representation of the three observed profiles and may reflect inter-individual differences in physiological response to CS associated to particular coping strategies. A more even INPs distribution could provide the population with a greater advantage when facing diverse environmental challenges. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=108 SRC="FIGDIR/small/577005v3_ufig1.gif" ALT="Figure 1"> View larger version (13K): org.highwire.dtl.DTLVardef@15b1dfdorg.highwire.dtl.DTLVardef@10df09dorg.highwire.dtl.DTLVardef@300532org.highwire.dtl.DTLVardef@a543e0_HPS_FORMAT_FIGEXP M_FIG C_FIG

physiology↗

bioRxiv2023

Ecological and life-history traits and their relationship with West Nile virus and Saint Louis Encephalitis virus exposure risk.

Host life-history traits can influence host-vector encounter rates, and so differentially determine the exposure risk of bird species. This modulation of host-virus encounters dynamics is especially important when facing "generalist" arboviruses like West Nile virus (WNV) and Saint Louis Encephalitis virus (SLEV). Using prevalence data collected by our laboratory since 2004, we tested several hypothesis that included birds ecological and life-history traits to determine which traits were better predictors of birds exposure risk to these arboviruses. By means of information-theoretic procedures and generalized mixed linear models, we observed that body mass was an important trait when predicting birds exposure risk to WNV and SLEV and migratory status significantly influenced birds exposure risk only to WNV. Our study highlights important traits to consider when studying the transmission system of these arboviruses, being useful to focus resources when characterizing viral transmission networks and discuss the repercussions of these traits over birds immune function throughout the pace of life syndrome and trade-offs theory.

ecology↗